CONTROL OF HEREDITY: EUGENICS 433 



Fecundity was relatively high but the death 

 rate was also very high, the excess of popula- 

 tion in each generation being carried off in 

 large numbers by war, pestilence and famine. 

 Then owing to the developments of science and 

 industry and to the opening up of new coun- 

 tries a period of remarkable expansion of pop- 

 ulation began. The population of Europe, 

 which was about 175 millions in 1800, increased 

 to 420 millions in 1900, and this in spite of the 

 fact that about 35 millions migrated from 

 Europe to new countries during this period. 

 This great increase in the population of Eu- 

 rope was due primarily to reduction of the 

 death rate since the birth rate also declined 

 slightly during this period, while in the newer 

 countries there was both an increase in the 

 birth rate and a decrease in the death rate. 



It is perhaps an open question how long the 

 advances of science in rendering available the 

 natural resources of the earth may be able to 

 keep pace with increasing population, but it is 

 evidently impossible for this great increase in 

 the population of the world to go on in- 

 definitely; sooner or later it must come to an 



